Casing hook for oil wells



B. DEDMAN CASING HOOK FOR OIL WELLS July 21, 1931.

Filed May 28. 1928 gums! 6 Sheets-Sheet l July 21, 1931. a. DEDMANCASING HOOK FOR OIL WELLS Filed May 28, 1928 6 Sheets-$heet 2 July 21-,1931. B. DEDMAN 1,315,290

CASING HOOK FOR OIL. WELLS Filed May 28, 1928 6 Sheets-Sheet 3 4 BryantDedzrzan July 21, 1931. B. DEDMAN CASING HOOK FOR OIL WELLS Filed May28, 1928 6 Sheets-Sheet 4 Bryant Dedman July 21, 1931. a. DEDMAN CASINGHOOK FOR OIL WELLS Filed May 28. 1928 6 Sheets-Sheet 5 gnuentoz .Bz ganiBadman abl ozwgta mu w w li b July 21, 1931. B. DEDMAN ,815,29

CASING HOOK FOR OIL WELLS Filed May 28. 1928 6 Sheets-Sheet 6 I I I I lI gmnntov Bl yani Badman Patented July 21, 1931 BRYANT DEDMAN, OF GLENELLYN, ILLINOIS CASING HOOK FOR OIL WELLS Application filed'May 28,1928. Serial No; 281,148.:

This invention relates to hooks of the type employed for supporting andhandling the casings and drill pipes and drill stems used inconstruction andoperationof oil and gas 5 wells.

Hooks of this type arecommonly used, in putting in or pulling wellcasings, to support a section of the casing while, it is" being screwedor unscrewed from theother sections. The separation of the sectionsis-effected by rotating the casing or drill rod, at a point below thejointto be broken, by means of a rotary table, while the section abovethe joint is held stationary. by suitable tongs or by holding stationarythe casing or drill rod, at a point below the joint to be broken, bymeans of a lockedandsuitably hushed rotary table while the section abovethe joint is rotated by means of tongs.

In either procedure some meansis-provided to take up the weight of theupper sec tion during the breaking of the joint; the weight of thesection rests on the screw threads of the joint and tends to grindofiand damage the threads. To obviate this damage to the screw threads andto'save time, it is common to support the section being removed by acasing hookprovided with a compression spring of suchstrength as tosupport the said section during the breaking ofthe taper threaded jointandlater after parting of the threads to automatically lift said sectionhigh enough to free it from all interference with its former matingmember.

0 Good examples of this type of casing hook is disclosed in the patentto Wigle, No.

14,253, reissued January 23rd, 1917'; Keim,

No. 1,572,390, February 9th, 1926; and Montgomery No. 1,536,617, May5th, 1925.

The main object of the present invention is to so contrive the springsthat the hook will have only a small excess spring lifting capacity atthe bottom of its travel over that required at the top of its travel andthereby provide ample section lifting capacity at the top of hook travelwithout excessive lifting pressure. on the partially disengaged threadsat or near the bottom of the hook .travel, that is, the pointat whichjointsare broken, and

thribles ble of handling these loads efliciently andwithoutunnecessary-shock within the hook mechanism itself.

In one typical size and type of. casing hooks, similar to VVigle incommon use, the

spring when merely supporting afourble load (that is at the top of thetravel o-f. the spring) is compressed about three inches (3") and, atthe bottom ofits travel.( when the spring efl ect is used toraise the.section during theunscrewing of the jointlhas a further compression-ofabout seven inches (7 making a total. compression of ten inches.

Now, since the: ordinary fourble load for this size hook is. about 2500lbs.,.and:this causes a three .inch compression of the spring, it isobvious that a ten inch compression of the spring means that a load ofover 80001bs. is imposed thereon at the start of the unscrewingoperation or over three times in' excess of thatrequired imposed uponpartially disengaged threads. The presentday made up fourble joints aredecidedly taper. threaded and separate at. about one inch of verticaltravelbetween the soulders; that is, when the spring wouldbe. compressedatabout 7,500 lbs.. Since. the load of the fourble alone at this instantof joint separation is only 2500 lbs., there is a force of 5000v lbs.acting. to throw the load upwardly with an evident tendency to rip outthreads immediately be fore and at the point of release. The shock onthe spring. andother mechanism of. the hook in this case is sometimesgreat enough to jar loose partsof the assembly; and in- .all events,imposes a great strain on such parts with consequentrapid deteriorationthereof.

Field operators complain about what they term unnecessary strength inthe springsemployed, and demand hooks. with lighter springs, but they donot realize that lighter springs in these old type hooks will not carrythe fourble load to the top of the loaded hook travel, which, to meetpresent day methods, should be at least 7 on the larger size hooks, thedistance required to lift the pin clear of the box when unscrewed.

The present invention is designed to practically eliminate excesspressure on partially unthreaded joints of the sections and excess shockto both joints and hook mechanism due to recoil when the section isreleased. It is designed to carry the fourble load, for example, 2500lbs. at the exert a lifting force only slightly in excess of the fourbleload, in this example, 3000 lbs, at the bottom of its travel. The resultof this arrangement is that the toggle and spring construction exertsufiicient force, at the instant of separation of a section from the casing, to lift the fourble load substantially without shock to the desiredupper limit of travel.

The main objects of the present invention are, therefore, to provide anauto-compensating spring swivel casing hook capable of eflicientlyhandling the thribles or fourbles in rotary drilling, and to eliminatepractically all shock to the parts of swivelled spring casing hooks dueto recoil of the springs.

Other objects of the invention will appear as the detailed descriptionproceeds.

In the drawings Figure 1 is a central vertical section through one formof the casing hook taken on the line 11 of Figure 2 Fig. 2 is a planview of the casing hook;

Fig. 3 is a section on the line 33 of Fig. 1;

Fig. 4 is a side elevation of the casing hook shown in Fig. 1 with partof a side plate broken away and a part section to show the internalconstruction of the casing hook;

Fig. 5 is a vertical section taken on the line 55 of Fig. 4;

Fig. 6 is a perspective view of a cylindrical pivot block in which thecasing hook supporting rod is mounted to slide;

Fig. 7 is a fragmentary sectional detail of the pivot connection betweenone of the spring elements and the sides of the casing enclosing themechanism of the casing hook;

Fig. 8 is a fragmentary central vertical section of a modification ofthis invention, the section being taken on the line 88 of Fig. 9;

Fig. 8 is a fragmentary detail illustrating means for adjustment to takecare of varying loads on the hook;

Fig. 8 is a section on the line 8 8 of Fig. 8

Fig. 8 is a side view taken on line 8-S of Fig. 8

Fig. 9 is a plan view of a modification shown in Fig. 8

top of its travel and to.

Fig. 10 is an elevation of the invention shown in Fig. 8, but drawn to asmaller scale and with parts of the casing broken away to disclose theparts co-operating with the invention more fully;

Fig. 11 is a fragmentary sectional elevation taken on the line 11-11 ofFig. 10;

Fig. 12 is an exploded perspective view of a cylindrical block in whichthe rod of the casing hook shown in Figs. 10 and 11 is adapted to slidewhen the parts are assembled;

Fig. 13 is a perspective view of the hooksupporting cylindrical rod;

Fig. 14 is a horizontal section taken on the line 1414 of Fig. 10;

Fig. 15 is a central vertical section of another modification of thisinvention taken on the line 15-15 of Fig. 17

Fig. 16 is a vertical section taken on the line 16-16 of Fig. 15;

Fig. 17 is a horizontal section taken on the line 1717 of Fig. 15;

Fig. 18 is a fragmentary plan View of the device shown in Fig. 15;

Fig. 19 is a horizontal section taken on the line 19-19 of Fig. 16;

Fig. 20 is a central vertical section taken on the line 20-2O of Fig.15;

Fig. 20 is a fragmentary detail illustrating another method of varyingthe spring compression to accommodate difierent loads; and

Figure 21 is a section taken on the line '2121 of Figure 20.

As shown in Figures 1,4, and 5, 1 designates a hook adapted to receivethe bights of a casing elevator 2 (see Figure 4). This hook 1 is formedintegrally with a cylindrical rod 3 slidably mounted in a rectangularblock 4 having trunnions 5 and 6 extending from opposite sides thereofto receive the apertures 7 and 8 in arms 9 and 10, respectively, of theyoke 11.

The block 4 is provided with a cylindrical bore 12 to form a guideway inwhich the rod 3 reciprocates. The rod 3 is provided with shoulders 13and 14 adapted to contact with the lower and upper ends, respectively,of block 4, at the upper and lower limits of travel, respectively, ofthe hook 1. In this particular case, the block 4 is seven inches shorterthan the distance between the shoulders 13 and 14 in order to restrictthe movements of the hook to the seven inch limit above referred to.

In order to facilitate assembling of the block 4 and the rod 3, theblock may be formed of two halves as shown in Fig. 12; and these halves,when assembled around rod 3, are riveted together and to the plates 17and 18 by means of the rivets 19.

The upper end of rod 3 is screwthreaded into a cap 20 which is thenlooked non-rotatably by a pin 21 to said end. The shoulder 14on rod 3 isformed by the lowerendof a bushing 22 which is slid-ably mounted on rod3; and race members -23"and 24 and rollers 25 of a roller bearing areinterposed b'etween the bottom of cap 20 andthe top of bushing 22.

The bushing 2 hasdiametrically opposite ears 26 and 27 formed thereon toreceive the bifurcated ends 28 and 29 of cylinders31 and 32,respectively; and pins 33 and34 serve to secure said'ends pivotally tosaid -ears26 and 27 respectively.

Cylindrical rods 35' and 36 are mounted slidably in cylinders 31 and 32,respectively, and have their lower ends pivotally connected by pivots 37and 38 to the side walls 39 and 40 of casing members 41 and 42.

The casing members 41 and 42 are spaced apart by and are fixed to theside plates 17 and 18 by the bolts 43 and nuts The pivots 37 and 38 eachcomprises a cy'- lindrical rod having a cap 45 formed on'one end to seatagainst one of the sides of members 41 and 42, and this rod has atransverse slot 46 cut in its periphery just where it passes through theside 39. (See Figure 7). A plate 47 is pivoted at one end to swingfreely on the wall 39 so that its end may seat in slot 46 and lock thepivot securely to the casing. To hold the plate 47 in looking posi tion,a machine screw 48 engaging a threaded hole in wall 39 may be used.

A pin or rod 49 having one end thereof secured by a chain 50 to th'ewall of casing member 42 to prevent loss thereof is shaped to slidethrough a bore 51 in the polygonal top of cap 20, to prevent turning ofthe hook and casing when it is desired to hold the same. This rod 49 hasa coilspring 52 secured to a pin 52 and abutting the cap 2.0; and alocking pin 53 passes diametrically through slot 53' in rod 49 nearitsother' end to be held in locking engagement with one end of cap 20 bythe compression of spring 52 after the pin 53 is beyond the slot 53 andturned one quarter of a revolution that is, 90 degrees toward thebottom.

The cylinders 31 and 32 and piston rods 35 and 36 are surrounded bycompression springs 54 and 55 which abut at their opposite ends againstshoulders 56 and 57'and 58 and 59 to form yielding supports for thesleeve 22.

The dotted line position of the parts (Figure 1) show that while thebushing 22 travels seven inches before it contacts with the upper end ofblock 4, the coil springs 54'and 55 are compressed only about one-halfof this distance and about one-fourth of their length. On the scaleshown in the drawing, the springs exert at their bottom position anupward force of about 3000 lbs; and at'the top of their travel, anupward force ofabout 2500 lbs. which is almost correct when the hook isto be used for handling 6 fourbles.

Since the upward force just referred to decreases with the extension ofthe spring during the unscrewing of the section, it follows that theforce remaining at the instant of separation of the section from thecasing (after: about 1 of travel) the force is just about sufiicient toraise the free section to the upper limit of its travel with very littleshock to the parts of the casing hook or to threaded joint beingseparated.

The form of the invention shown in Figures 8 to 14, inclusive, issubstantially the same as that already described, so far as theprinciple involved in its operation is concerned. This form does notinclude any roller bearings to permit the hook supporting rod to rotate;and it is therefore assumed thatthe rotary movement can be taken care ofby a common type double swivel roller bearing hook and suspending (bailshown) the section above the joint being broken.

As shown in Figures 8 and 10, the bail 60 of a common doubie swivelhook, as at present used, to permit turning of the hook where noprovision is made in the casing for this purpose, is hung from a bailhaving bifurcatedarms 61 and 62 provided with alined bearing apertures63 and 64, respectively, to receivea pivot pin 65. The pin 65 isprovided with a head 66 at one end thereof, and has a retaining washer67 secured to its other end by. a headed screw 68 the pin being securedin said apertures 63 and 64 by said head and washer. The bail 60receives the usual gudgeon 60' for supporting the common double swivelhook (not shown).

The pin 65 is rotatably mounted in a. horizontal bore 69 formed inbearing cap 70 which is screwthreaded and pinned on to the lower end ofa cylindrical rod 71 slidably vertically in arectangular cylinder block72.

The block 7 2 is formed in two parts 73 and 74, provided with suitablecooperating recesses and projections to prevent lengthwise separation ofsaid parts when assembled. These parts 73 and 74 are provided withregistering bores 75 to receive bolts 76 for securing said partstogether between casing plates 77 and 78. The parts 73 and 74 are alsoprovided with semi-cylindrical recesses 79 and 80, adapted, when theparts are assembled, to form a cylinder in which rod 71 is mounted toslide.

The upper end of rod 71 is provided with a. shoulder 81 adapted tocontact with the upper end of block 72 to limit the downward movement ofthe hook 60; and the rod 71.is provided with a key slot 82 adapted toreceive a key plate 83 seated in a recess 84, formed in the part 74, andprovided with apertures 85 adapted to register with the bores 75. Theplate 83 is securely held in position by the bolts 76 when the parts 73and 74 are assembled.

The plates 77 and 78, between which the cylinder block 72 is bolted, arebolted in turn to casing members 86 and 87 by bolts 88, and extendupwardly above said members to form bearing plates 89 and 90, for apivot pin 91. \Vaehers 92 and 93 space the plates 89 and 90 from sideplates 9 1 and 95, of a traveling block 96, apertured to providebearings in which the projecting ends of the pivot 91 are seated.

The upper end of rod 21 is flattened on opposite sides to provideoppositely disposed bearing lugs 97 and 98 apertured to receive pivotpins 99 and 100, respectively. Cylinders 101 and 102 are swung on thepins 99 and 100, respectively; and pistons 103 and slid able in saidcylinders 101 and 102 are pivoted to the casing members 86 and 87 onpivots 105 and 106, respectively, the pivots being detachably secured tothe casing members by locking plates 107 and 108 in the same manner asthe corresponding pivots of the construction shown in Figure 4:.

The cylinders 101 and 102 and the pistons 103 and 104 are provided withshoulders 109, 110, 111 and 112 to form abutments for the ends ofcompression springs 113 and 11 1.

The modification just described operates similarly to that shown inFigures 1 to 7 except that the hook supporting rod is keyed againstrotation in the block 7'2.

The modification shown in Figures to shows a very compact arrangement ofparts in which the toggle linkages, connecting the springs supports tothe hook, are floated on bell cranks. In this form of the invention thecasing comprises a pair of substantially circular plates 115 and 116having tween the cap 131 and alined pivots 117 and 118 secured thereto,to pivot the arms 119 and 120 of a yoke for sup porting the casing hook.

The arcuate ends 121 and 122 are hinged at their upper ends on pins 123and 124, respectively; and have their free ends 125 and 126 flattened tobe bolted to the lower end of the cylinder block 127 which is bolted orotherwise fixed between the sides 115 and 116 by bolts 128.

The hook rod 29 is mounted to slide verticaliy in block 127, and isprovided with a shoulder 130 to limit the upward vertical movement ofthe rod in the block. The upper end of the rod 129 is screw threaded andpinned into cap 131, and roller bearing members 132, 133 and 13 1 areinterposed bea sleeve 135 to permit the rod to rotate freely in block127 and relatii .y to sleeve 135; the lower end 130 of whicn forms astop to limit the downward movement of the rod 129.

The spring supports for the hook in this form of the invention aresimilar to those shown in the forms already described, but are pivotedto the casing so as to normally stand substantially vertical. Thesesupports comprise lower piston members 136' and 137 pivoted at theirlower ends on pivot pins 138 and 139, respectively, secured by cotterpins 1&0 and 141 between the side plates 115 and 116.

The lower ends of members 136 and 137 are expanded laterally to formbushings 142, extending between the side plates 115 and 116 to centerthe supports between said plates; and the cylindrical piston partsthereof are capped by cylinders 1 12 and 14:3 sliding thereon. The upperends 14% and 145 of these cylinders are flattened to form bearings forpivot pins 1 16 and 147 which are locked in said ends by the set screws148 and 149.

To connect the pivot pins 146 and 1 17 to the hook rod 129, bell cranks150 and 151 are pivoted to swing on pins 152 and 153 fixed to the sideplates 115 and 116. The bell cranl-t 150 comprises a bushing 15 1extending between the walls 115 and 116 and pivoted on pivot 152. Twoarms, 155 and 156 extend radially from said bushing and have their freeends pivoted to the lower ends oi links 157 and 158 which are pivoted toopposite ends or" a bearing ear 159 formed on the sleeve 135.

The upper arms 160 or bell crank 150 are p otally connected to pivot1&6, while the upper arms 161 of bell crank 151 are pivotally connectedto the pivot 1&7. The links 162 and 163 are pivot-ally connected at oneend to a bearing ear 164 also formed on the sleeve 135 opposite to ear159 and at their lower ends are pivoted to arms 165 and 166.

The links and bell cranks are symmetrically arranged relative to theaxis of the rod 129, and serve to convert a small compression of thesprings 167 and 168 into a comparatively large downward movement of therod 129, and vice versa.

Tn all the modifications disclosed herein,

the side plates or hinged end plates may be readily moved to give accessto the parts enclosed in the casing whenever it becomes necessary toreplace or repair parts thereof. In all of these devires the increasingmechanical advantage of the toggle construction offsets the decrease inspring pressure resulting from decrease in compression from normalspring compression in cases where the spring carries the whole loaddirectly.

By proper design the mechanism could be designed to provide he same loadc Tying capacities at the top and bottom of the spring travel. However,the constructions disclosed herein provide an excess load carryingcapacity at the bottom of the spring travel in order to providesufiicient lifting force at the bottom to accelerate and carry the loadthe usual seven inches to the top of the spring travel.

The seven inch travel of the load is the normal travel required bypresent day construction. It must be understood, however,

that this.-invention is; not to, be. limited in any;' way;. to.constructions designed to effect thIlSaSGVQDJ inch. lift, asthepartsmaybe relativel y proportioned andr designed to take care of any desiredlift. The seven inch lift issmere-ln described herein in order to give aspecific; example of? the construction and uses of the invention.

The compression of the springs in these devices may be regulated byinserting washers, similarto washer 170 (Fig. 20) between the ends ofthe springs and the abutment shoulders on the cylinders and pistonsaround which the springs are coiled.

The compression of the springs to accommodate different loads may beregulated by mounting the pivot pins of the springs in bearingseccentrically mounted 011 the casing. For example in Figs. 8 S and 8 thepivot pin 106 is rotatably mounted in the casing and extends beyond theopposite sides of the casing.

One side of the casing has a square opening 171 adapted to receive asquared por- --tion 172 of the pin 106 and the latter has a spline 173engaging a corresponding slot in the eccentric bearing arbor or cylinder174. Beyond the squared portion is an enlarged head 175 preferablyflattened on two "sides and the opposite end of the pin is threaded toreceive a nut 176. By unscrewing the nut 176, the pin may be displacedaxially to disengage the squared portion 172 from the opening '171 whereit normally holds the pin 106 from turning, so that by applying a wrenchtothe head 175, the pin 106 may be turned to correspondingly rotate orturn the eccentric collar or cylinder 174: whereby to adjust thecompression or tension of the spring without disconnecting the parts.Then, by again engaging the squared portion 172 with the opening 171 andtightening on the nut 176, the parts are held in adjusted position andthe shaft or pin "106 held from turning. By having the hearing at theend of the piston 10 1 enlarged to rotatably receive the cylinder andthe latter keyed to the pin, it is obvious that the ad justment iscontrolled by the rotation of the pin or shaft, 106*. By this means,rotation of the pin causes rotation of the cylinder to raise or lowerthe piston 104 against the pressure of the spring 114-.

The use of shims or washers to regulate the initial spring pressurewould necessarily involve disassembling of the several parts for each orthe two different adjustments 5, whereas the eccentric mounting could beoperated from outside the casing to effect the C6; adjustment withoutdisconnecting any of the parts of the hook.

What I claim is: 1. A block, a hook rod' slidable and rotatable in saidblock, compression springs K pivoted at one end to said block onopposite sides of said rod, and means connecting the otlierends of saidsprings pivotally to said ro 2. A block, a hook rod slidably journaledin said block, and toggle mechanism pivoted to said block and pivotallyconnected to said rod tosupport said rod yieldingly on said block.

3. A block, a hook rod reciprocable in said block, means on said blockand said rod to limit the reciprocation of said rod, and means pivotedto said block on opposite sides of said rod to support the rodyieldingly in one of its limits of reciprocation.

4. A" block, a guide fixed thereto, a hook rod' gageable with the endsof said guide, spring members having one end of each pivoted tosaidblock on opposite sides of said rod and connected to said rod to form atoggle linkage supporting said rod with one of its stops in contact withone end of said guide.

6. A block, a guide integral with said block, a hook rod slidable insaid guide, means on opposite sides of said guide carried by said rodthrough a predetermined distance in either direction, compressibleyielding means pivoted to said block, and rod to resist sliding thereofin one direction and arranged so thatcompression of said means throughapredetermined distance results in movement of said rod through a greaterdistance.

7. A block, a guide fixed to said block, a hook rod slidable in saidguide and having a shoulder engageable with one end of said guide, a capfixed to the other end of said rod,

a sleeve rotatable on said rodbetween said cap and the other end of saidguide, an antifrlction bearing between said sleeve and cap,

and yielding means pivoted to said block and sleeve to hold said rodnormally with said shoulder against said one end of the guide.

8. A block, a cylindrical guide fixed to said block, a hook rod slidablyand rotatably mounted in said guide, a shoulder on said rod engageablewith one end of said guide, a stop fixed to said rod yieldable togglemechanism pivoted to said block, and slidably and rotatably connected tosaid rod to engage said stop and maintain said rod normally with itsshoulder in contact with the end of said guide, said rod being slidablethrough said block a predetermined distance against the yielding.resistance of said mechanism.

9. A block, a rod slidably and rotatably mounted on said block, meansfor limiting. the'sliding movements of said-rod in each direction onsaid block, and yielding toggle mined position on said block.

10. A block, an anti-friction bearing, a hook supported by said bearing,resilient toggle mechanism symmetrically arranged relative to said hookand supporting said bearing, and means on said block to carry the loadwhen the said hook ias been moved a predetermined distance from itsnormal toggle supported position.

11. A block, an anti-friction bearing, a hook passing through andsupported by said bearing, resilient toggle mechanism pivoted to saidblock and including a sleeve slidable on said hook and in supportingcontact with said bearing, and a stop member on said block positioned tosupport said sleeve and carry the load on said hook when the saidmechanism has been moved to a predetermined position.

12. A block, an anti-friction bearing, a hook passing through andsupported by said bearing to rotate freely thereon, a sleeve rotatableon said hook, resilient means pivotally connected to opposite sides ofsaid sleeve and to said block, and a stop fixed to said block to supportsaid sleeve and bearing when the resilient means been compressed apredetermined distance.

13. A block, an anti-friction bearing a hook passing through andsupported by said bearing to rotate freely thereon, a sleeve rotatableon said hook and in supporting contact with said bearing, resilientmeans pivoted to said block and connected to said sleeve to support saidbearing yieldingly, and a stop on said block to engage said sleeve andtransfer the load from said resilient means to said block.

14. A block, an anti-friction bearing, a hook passing through andsupported by said bearing, a sleeve rotatable, on said hook, yieldingmeans pivoted to said block and sleeve to support said bearing, andmeans to relieve the load on said yielding means when the sleeve hasmoved through a predetermined distance.

15. A block, a hook, a sleeve in which said hook is rotatably supported,spring members pivoted to said block on opposite sides of said hook,bell cranks pivoted to said block on opposite sides of said hook andhaving one arm of each pivoted to the free end of the adjacent springmember, and links pivotally connecting the other arms of said bellcranks to said sleeve.

16. In a casing hook for oil wells and the like, a block, a guide fixedto said block, a rod slidable in said guide and having a shoulderengageable with one end of said guide, a shoulder at the other end ofsaid rod, a sleeve rotatable on said rod between said shoulder and theother end of said guide, an

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